Strange ng-if behavior

HTML

<link rel="stylesheet" href="//netdna.bootstrapcdn.com/font-awesome/3.2.1/css/font-awesome.min.css">
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.2.0/angular.js"></script>
<div ng-controller="myCtrl">

    <button ng-click="seeTheBug()">See the bug</button>
    <h2 ng-if="something">BUG</h2>
    
</div>

CoffeeScript

demo = angular.module 'demo', []

demo.controller 'myCtrl', ($scope) ->
    $scope.seeTheBug = =>
        $scope.something = {};

angular.bootstrap document, ['demo']